In ArF liquid immersion lithography and extreme ultraviolet (EUV) lithography, processing dimensions of resist line widths have been required to be finer. In formations of such fine resist patterns, the smaller the contact area between a resist pattern and a ground is, the larger the aspect ratio (the height of the resist pattern/the line width of the resist pattern) is, which is likely to cause collapse of the resist pattern. Thus, a resist underlayer film (anti-reflective coating) that is in contact with a resist pattern has been required to be highly adhesive to the resist pattern in order to avoid collapse of the resist pattern.
A resist underlayer film-forming composition has been disclosed that employs a lactone structure as a structural component for achieving high adhesiveness to a resist pattern. A resist underlayer film formed with the composition has improved adhesiveness to a resist pattern to be obtained (Patent Document 1). In other words, by using a structure having a polar moiety such as a lactone structure as a structural component of a resist underlayer film-forming composition, adhesiveness to a resist pattern is expected to be improved, and collapse of a resist pattern is expected to be prevented even in a fine resist pattern.
Unfortunately, in a lithography process requiring formation of much finer resist patterns, such as ArF liquid immersion lithography and extreme ultraviolet (EUV) lithography, containing only a lactone structure in a resist underlayer film-forming composition as a structural component does not sufficiently prevent collapse of a resist pattern.